elixir: use a requirement with a default formula for erlang
postgres usage in caveats; Closes #21920

As a PostgreSQL n00b, this is the information I wanted.

Ideally we’d set a default configuration location for postgres to look, however apparently, this is not possible.

Side note: it's about time we split caveats out. One of these is advise for failed builds, and I just added usage. Usage is hardly caveats, but generally usage is cool and we should encourage it as a separate section, and encourage people to add links perhaps.
sshuttle: fix checksum

Closes #22334.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
tinc 1.0.22

Updated tinc to 1.0.22

Closes #22330.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
node devel 0.11.7

Closes #22322.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
unrar 5.0.11

Closes #22326.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
Suggest installing pip via easy_install
node 0.10.18

Closes #22316.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
node: fix compilation on 10.6
homebank 4.5.2

Closes #22341.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
the_silver_searcher: install bash-completion script

Closes #22306.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>
pyqt5 5.0.1

Closes #22340.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>